"BFJ" (reversible, size, labeled) transform of 2,1,1,1...

Terms

a(0) =1a(1) =2a(2) =1a(3) =7a(4) =9a(5) =21a(6) =388a(7) =701a(8) =2789a(9) =8581a(10) =325116a(11) =725715a(12) =3549362a(13) =15974921a(14) =77157109a(15) =4774872394a(16) =13166159997a(17) =74350315389a(18) =375874959532